It even had a letter hidden in its pages. It's from one high school (maybe college) kid to another about how he made the basketball team and has finally found time to send his friend this book. Given that we live in Indiana (you know, Hoosier basketball) that's a pretty exciting thing to find in an old book.
But the funniest thing happened when I finished celebrating her find and went back to looking for other books. She was sitting under a table, flipping through the book, and suddenly exclaimed:
"Look, Mama! It's a secret code!"
"Cool! Let me look..."
If you've been following this blog for a while you'll know my seven year old is basically fluent in mental sums and differences and visual math for her age, but has only experienced the symbolic realm in a cursory way. It's been working for us so far. Yesterday she 'discovered' a "fourthagon" in our lunch table (short video here). And, today she was trying to convince me to top off her savings for a set of walkie-talkies. She's got $7.68 saved already and was imagining a set might cost around $10. We were out for a walk when suddenly she stopped stock still and turned inward. Then she said,
"Mama, if you could give me $2.33 I'd be able to buy those walkie-talkies."
"No," I said, "I think this is something you'll need to save for if you really want it." Secretly I was completely surprised and impressed that she had figured that all out in her head within one penny.
I was tickled at her reaction to that page in the Solid Geometry book too. Without too much giggling I said:
"You're right, that is sort of a secret code. It's called mathematical notation. After you understand the math concepts you'll learn the way to write them down -- it's the language of math."
I'm still giggling about the whole secret code thing -- it brings to mind a secret network of mathematical spies, or some sort of secret underground club, communicating with only the most esoteric of notation, an unbreakable code that stands for all time...[cue dramatic music].
I think she nailed it. Out of the mouths of babes, right? What do you think?